1. Field of the Invention
The present invention relates to a liquid crystal panel in which countermeasures against external pressure are taken, and a liquid crystal display device.
2. Description of the Related Art
A liquid crystal display device has advantages in terms of thinness, light weight, and low electric power consumption. Thus, the liquid crystal display device has been widely used in an electric device for mobile applications, such as a cell-phone, and a digital camera. The liquid crystal display device includes a liquid crystal panel in which a liquid crystal layer is sealed between a pair of substrates. In the liquid crystal display device, light emitted from a backlight which is arranged on a back face of the liquid crystal panel is modulated in the liquid crystal panel, and the modulated light is output from a front face of the liquid crystal panel to the outside, thereby an image display is performed.
In recent years, a sensor function called a touch panel has been installed in the liquid crystal display device. A user's finger or pen touches an icon or the like displayed on a screen, thereby the touch panel inputs data. Usually, the touch panel is arranged on a contact face (that is, the top surface of the liquid crystal display device) with which the finger, the pen, or the like is in contact, so that instructions indicated on the screen of the liquid crystal display device may be selected with the finger, the pen, or the like. The touch panel detects a position where the finger, the pen, or the like is in contact with, and outputs the instruction corresponding to the contact position, as an input signal. In this manner, in the touch panel, it is unnecessary to provide a keyboard and a mouse typically used in a computer or the like, and a keypad typically used in a mobile device such as a cell-phone. Therefore, the use of the touch panel tends to be spread.
However, there are some issues in the above-described touch panel. For example, in the case where the touch panel is arranged on the top surface of the liquid crystal display device, the liquid crystal display device itself increases in thickness and size. Moreover, there are such issues that optical characteristics are deteriorated due to influence of a refractive interface, and the manufacture cost is up since the touch panel is manufactured separately from the liquid crystal panel. Thus, in recent years, it is considered to integrally form the liquid crystal panel and the touch panel. With such integration, several merits may be obtained, in addition to the solution for the issue indicated above as an example. For example, since an existing wiring (for example, an array wiring for display) in the liquid crystal panel may be used in common, it is possible to obtain additional functions such as high resolution and multipoint detection.
For example, in Japanese Unexamined Patent Publication No. 2007-95044, a liquid crystal display device as the integrated liquid crystal display device is proposed. When external pressure with a touch of the finger, the pen, or the like is applied to the contact face, an electrode in a facing substrate and an electrode in an array substrate are electrically in contact with each other, thereby a mechanism installed in the liquid crystal display device detects the contact position.